Tue, 30 Oct 2012
Bike Lights
I have a new personal project: I am trying to build a set of lights for my bike. So far my setup is quite simple: I use a 700 mA Buck Puck current regulator to feed a front Cree XM-L white LED and three rear 350 mA red LEDs. It can only be switched on or off, and cannot blink at all. So I wanted to make something more sophisticated.
I have been playing with electronics many years ago in my teen-age years, but I have been doing only software since then. So I have taken this as an opportunity to find out what progress the world of DYI electronics has made, and to learn programming of microcontrollers. I want the resulting electronics to have the following features:
- LED drivers for high-power LEDs:
- Atmel AVR Tiny CPU, programmable in-system (various blinking modes, etc.).
- Power: 7 to 12 V battery pack (either lithium or NiMH).
- Ambient light sensor (for automatically setting the mode depending on the conditions).
- Battery voltage monitoring.
- Cycle computer illumination LED.
- Two status LEDs.
- Two buttons for adjusting modes, switching on/off, etc.
- Software on/off.
- High-power software switched output driven by a MOSFET transistor (I don't know the purpose yet, I just had a spare pin and MOSFET :-).
I have managed to learn how to use the gEDA suite of tools, and created my first PCB with it. Yesterday I have sent the result to the fab. Anyway, I have made the Project Bike Lights page for my project, where it is possible to watch the progress or look at the firmware code, schematics, and PCB design.
Sat, 13 Oct 2012
Those Annoying Endorsements
Recently LinkedIn has added a new feature, endorsements. The most annoying thing is that the requests for endorsements are now near the top of the page, and people are clicking on it. So I have several mails each day saying "$somebody has endorsed you!" (with an "and you are expected to return the favor" subliminal message). So, my dear LinkedIn contacts: feel free to not endorse me and don't bother to write recommendations, as I don't plan to do the same either.
Fri, 12 Oct 2012
Failed SSD
Yesterday I went to a meeting and brought my laptop with me. I made
notes to a text file, and after the meeting closed the lid (my laptop
is configured to suspend then) and went away. After returning to my
office I have opened my laptop and seen only error messages from
the sda drive.
The drive was totally dead, and did not work even in another computer.
After plugging it in the SATA controller only printed something like
"resetting SATA channel", so it did notice something has
been plugged in, but nothing more. I had to teach my UNIX course in two
hours, so I had to quickly find a replacement, install a new system,
and configure it for presentation. Fortunately, I had a "spare" 2.5" drive
prepared as a replacement of the root FS of my workstation. So I deleted
the already configured system for my workstation, and used that.
Have you anybody seen a similar problem? The drive was "iops-optimized" OCZ Vertex II, about a year old. Fortunately, I use LUKS, so I can send it back to the vendor without worrying about my data.
Tue, 09 Oct 2012
Zacyklení 2012
I like outdoor puzzle-solving games, and last weekend I managed to take part in a really special kind of puzzle-solving competition:
Zacyklení is a puzzle-solving outdoor game for cyclists. And what is even more interesting, we have managed to create a purely recumbent team for this game. Those who can read Czech, here is the report from the game. Those who can't, follow the link anyway for more photos :-). We have not made it in time, but among all the teams we have finished somewhere around 5th place. Congratulations to the winners, and thanks to the organising team!